wizardstore.java

Java的面向对象数据库系统的源代码

    }


    public synchronized ObjectContainer newContainerAndLock(Transaction ta, OzoneCompatible target, ObjectID objID,
                                                                  Permissions permissions, int lockLevel) throws Exception {


        StorageObjectContainer container = new WizardObjectContainer(objID);

        if (target != null) {
            container.setTarget(target);
        }

        clusterStore.registerContainerAndLock(container, permissions, ta, lockLevel);

        boolean alright = false;

        try {

            garbageCollector.notifyNewObjectContainer(container);

            WizardTransaction wizardTa = (WizardTransaction) ta;
            ClusterID cid = container.getCluster().clusterID();
            ObjectID oid = container.id();

            if (env.logWriter.hasTarget(LogWriter.DEBUG3)) {
                env.logWriter.newEntry(this, "newContainer(): cid=" + cid + ",oid=" + oid + ".", LogWriter.DEBUG3);
            }

            wizardTa.idTable.addForKey(cid, oid);
            wizardTa.idTableChanges_push(new IDTableChange(oid, cid, IDTableChange.STATE_ADDED));

            alright = true;

            return container;
        } finally {
            if (!alright) {
                container.getCluster().lock().release(ta);
                container.unpin();
            }
        }
    }


    //    public synchronized void deleteContainer (Transaction ta, ObjectContainer _container)
    //            throws Exception {
    //        if (env.logWriter.hasTarget (LogWriter.DEBUG3))
    //            env.logWriter.newEntry (this, "deleteContainer()", LogWriter.DEBUG3);
    //
    //        WizardObjectContainer container = (WizardObjectContainer)_container;
    //        taData.idTableChanges.push (new IDTableChange (oid, cid, IDTableChange.STATE_ADDED));


    public void updateLockLevel(Transaction _ta, ObjectContainer _container) throws IOException {
        if (env.logWriter.hasTarget(LogWriter.DEBUG3)) {
            env.logWriter.newEntry(this, "updateLockLevel()", LogWriter.DEBUG3);
        }

        if (_container instanceof WizardObjectContainer) {
            StorageObjectContainer container = (StorageObjectContainer) _container;
            container.getCluster().updateLockLevel(_ta);

            WizardTransaction wizardTa = (WizardTransaction) _ta;
            wizardTa.idTable.addForKey(container.getCluster().clusterID(), container.id());
        }
    }


    /**
     * Returns the ObjectContainer for the given ObjectID or null if there is
     * no such container.<p>
     If an ObjectContainer is returned, it is pinned once.
     Thus, the caller has to ensure that the ObjectContainer is unpinned as soon as it is not needed anymore.
     *
     * @param ta the Transaction for within the container is requested or null.
     *
     * Impl. Note: For performance reasons this is the only method of this Store
     * that is not synchronized. This will not cause problems because the only
     * field that is updated inside the method (currentContainer) does not need
     * to be stable while this method is running.
     */
    public ObjectContainer containerForID(Transaction ta, ObjectID id) throws ObjectNotFoundException, IOException, ClassNotFoundException {

        StorageObjectContainer container = null;
        WizardTransaction wizardTa = (WizardTransaction) ta;

        // search the LRU cluster to speed things up; since this is not
        // synchronized, checking and accessing currentCluster must be done in
        // one line to avoid other thread to change the variable in between
        //        container = (currentCluster != null && currentCluster.lock != null) ? currentCluster.containerForID (id) : null;
        //        if (container != null) {
        //           // System.out.print ("+");
        //            return container.isDeleted() ? null : container;
        //            }

        ClusterID cid = null;

        // search members of current ta first
        if (ta != null) {
            DxMap taDataIDTable = wizardTa.idTable;
            cid = (ClusterID) taDataIDTable.elementForKey(id);

            if (cid == null && wizardTa.lrucid != null) {
                org.ozoneDB.core.storage.Cluster lru = clusterStore.loadCluster(wizardTa.lrucid, true);

                if (lru != null) {
                    try {
                        container = lru.lock() != null ? lru.containerForID(id) : null;
                        if (container != null) {
                            // System.out.print ("+");
                            if (container.isDeleted()) {
                                return null;
                            } else {
                                container.pin();
                                return container;
                            }
                        }
                    } finally {
                        if (lru instanceof WizardCluster) {
                            ((WizardCluster)lru).unpin();
                        }
                    }
                }
            }
        }

        // search global table ONLY if ta doesn't contain the container
        if (cid == null) {
            cid = (ClusterID) idTable.elementForKey(id);
        }

//				env.logWriter.newEntry( this, "containerForID(): id="+id+",cid="+cid+".", LogWriter.DEBUG3 );

        if (cid == null) {
            return null;
        } else {
            // System.out.println ("-");
            org.ozoneDB.core.storage.Cluster cluster = clusterStore.loadCluster(cid, true);

            if (cluster == null) {
                throw new ObjectNotFoundException("No object registered for ID: " + id);
            }

            try {
                if (wizardTa != null) {
                    wizardTa.lrucid = cid;
                }

                try {
                    container = cluster.containerForID(id);

                    if (container.isDeleted()) {
                        return null;
                    } else {
                        container.pin();
                        return container;
                    }
                } catch (NullPointerException e) {
                    env.logWriter.newEntry(this, "NullPointerException during " + cluster + ".containerForID(" + id + "). We were able to load a cluster for that ID but the cluster did not contain the container. This is an inconsistent view.", e, LogWriter.ERROR);
                    throw e;
                }

            } finally {
                if (cluster instanceof WizardCluster) {
                    ((WizardCluster)cluster).unpin();
                }
            }
        }
    }

    public DxSet objectNames(Transaction ta) {
        env.logWriter.newEntry(this, "Returning objectnames", LogWriter.DEBUG);

        return nameTable.keySet();
    }

    public synchronized ObjectContainer containerForName(Transaction ta, String name) throws Exception {
        if (name == null) {
            return null;
        }

        WizardTransaction wizardTa = (WizardTransaction) ta;

        if (ta == null || wizardTa.nameTable == null) {
            ObjectID oid = (ObjectID) nameTable.elementForKey(name);
            return oid != null ? containerForID(ta, oid) : null;
        }

        if (ta != null) {
            ObjectID oid = (ObjectID) wizardTa.nameTable.elementForKey(name);
            return oid != null ? containerForID(ta, oid) : null;
        }
        return null;
    }


    public synchronized void nameContainer(Transaction ta, ObjectContainer container, String name)
            throws PermissionDeniedException {

        if (env.logWriter.hasTarget(LogWriter.DEBUG3)) {
            env.logWriter.newEntry(this, "nameContainer(), nameTable=" + nameTable + ".", LogWriter.DEBUG3);
        }

        WizardTransaction wizardTa = (WizardTransaction) ta;
        if (wizardTa.nameTable == null) {
            Object o = null;
            try {
                java.lang.reflect.Method method = nameTable.getClass().getDeclaredMethod("clone", null);
                if (env.logWriter.hasTarget(LogWriter.DEBUG)) {
                    env.logWriter.newEntry(this, "nameContainer(), nameTable=" + nameTable + ", nameTable.getClass().getDeclaredMethod(\"clone\",null)=" + method + ".", LogWriter.DEBUG);
                }
                o = method.invoke(nameTable, null);
            } catch (Exception e) {
                env.logWriter.newEntry(this, "nameContainer(): caught: ", e, LogWriter.INFO);
            }

            if (o == null) {
                o = nameTable.clone();
            }


            wizardTa.nameTable = (DxMap) o;
        }

        String oldName = container.name();
        if (oldName != null) {
            wizardTa.nameTable.removeForKey(oldName);
            wizardTa.nameTableChanges_push(new NameTableChange(container.id(), oldName,
                                                             NameTableChange.STATE_REMOVED));
        }

        container.nameTarget(name);

        if (name != null) {
            if (oldName == null) {
                garbageCollector.notifyNewObjectName(container);
            }
            wizardTa.nameTable.addForKey(container.id(), name);
            wizardTa.nameTableChanges_push(new NameTableChange(container.id(), name, NameTableChange.STATE_ADDED));
        }
    }


    public synchronized DxBag clusterOfID(ObjectID id) throws Exception {
        if (env.logWriter.hasTarget(LogWriter.DEBUG3)) {
            env.logWriter.newEntry(this, "clusterOfID()", LogWriter.DEBUG3);
        }

        ClusterID cid = (ClusterID) idTable.elementForKey(id);
        if (cid == null) {
            throw new ObjectNotFoundException("");
        }

        org.ozoneDB.core.storage.Cluster cluster = clusterStore.loadCluster(cid, true);

        try {

            DxBag result = new DxArrayBag();
            DxIterator it = cluster.containers().iterator();
            while (it.next() != null) {
                ObjectContainer container = (ObjectContainer) it.object();
                result.add(container.id());
            }
            return result;
        } finally {
            if (cluster instanceof WizardCluster) {
                ((WizardCluster)cluster).unpin();
            }
        }
    }


    public synchronized void prepareCommitTransaction(Transaction ta) throws IOException, ClassNotFoundException {
        if (env.logWriter.hasTarget(LogWriter.DEBUG3)) {
            env.logWriter.newEntry(this, "prepareCommitTransaction()", LogWriter.DEBUG3);
        }

        WizardTransaction wizardTa = (WizardTransaction) ta;

        // initialize transaction data fields
        wizardTa.commitClusterIDs = new DxHashSet(64);

        DxIterator it = wizardTa.idTable.iterator();
//      env.logWriter.newEntry( this, "idTable count: " + taData.idTable.count(), LogWriter.DEBUG2 );
        ClusterID cid;

        while ((cid = (ClusterID) it.next()) != null) {
            if (env.logWriter.hasTarget(LogWriter.DEBUG3)) {